1. Field of the Disclosure
The present disclosure relates to a bonding system and a bonding method, and more particularly to a bonding system for optical alignment and a bonding method for coupling an optical semiconductor with an optical waveguide.
2. Description of Related Art
In the field of computer and communication, the demands on high transmission speed and compactness of a product are the driving force for replacing the traditional electronic transmission with optical transmission. There are various products and technologies that are or are evolving to be the mainstreams in the market, and examples of such include optical USB, silicon transceiver and silicon photonics, in which data is transferred among devices by optical rays.
In an optoelectronic system, such as those discussed above, it is customary that a LD (laser diode) chip and a silicon waveguide are optically coupled together. In order to achieve a 50% coupling efficiency between the LD chip and the silicon waveguide, the alignment tolerance is required to be within 1 μm (micron). Conventionally, a LD chip is optically coupled to an optical waveguide formed on a substrate by monitoring the intensity of light outputted from the optical fiber in an oscillating state of the LD chip. The position of the optical waveguide is adjusted such that the amount of light is maximized. However, this type of active alignment techniques is labor-intensive and the equipments are expensive and complicated.
Accordingly, passive alignment techniques are developed in which a LD chip and an optical fiber are disposed at specific positions, and an operation is performed to mount and to couple the LD chip and the optical fiber together. Although there are existing bonding platforms capable to achieve the tolerance requirement, these machines are also expensive and the throughput is low.
It has been demonstrated that the overall cost of all optoelectronic systems is dominated by the packaging, and alignment is the major contribution of the packaging cost. Hence, it is critical to provide a cost-effective assembly process for accelerating the growth of optoelectronic technologies and the yield of optoelectronic products.